mvc4数据注释比较两个日期

Question

我的模型中有这两个字段:

[Required(ErrorMessage="The start date is required")]
[Display(Name="Start Date")]
[DisplayFormat(DataFormatString = "{0,d}")]
public DateTime startDate { get; set; }

[Required(ErrorMessage="The end date is required")]
[Display(Name="End Date")]
[DisplayFormat(DataFormatString = "{0,d}")]
public DateTime endDate{ get; set; }

我要求endDate必须大于startDate.我试过使用,[Compare("startDate")]但这只适用于相同的操作.

我应该用什么来做"大于"的操作？

Answer 1

看看Fluent验证或MVC Foolproof验证:这些可以帮助你很多.

例如,使用Foolproof,[GreaterThan("StartDate")]您可以在日期属性上使用注释.

或者,如果您不想使用其他库,则可以通过IValidatableObject在模型上实现来实现自己的自定义验证:

public class ViewModel: IValidatableObject
{
    [Required]
    public DateTime StartDate { get; set; }
    [Required]    
    public DateTime EndDate { get; set; } 

    public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
    {
       if (EndDate < StartDate)
       {
           yield return 
             new ValidationResult(errorMessage: "EndDate must be greater than StartDate",
                                  memberNames: new[] { "EndDate" });
       }
    }
}

Answer 2

IValidatableObject接口为验证对象提供了一种实现IValidatableObject.Validate(ValidationContext validationContext)方法的方法.此方法始终返回IEnumerable对象.这就是为什么你应该创建ValidationResult对象的列表,并将错误添加到此并返回.空列表表示验证您的条件.在mvc 4中如下...

 public class LibProject : IValidatableObject
{
    [Required(ErrorMessage="Project name required")]

    public string Project_name { get; set; }
    [Required(ErrorMessage = "Job no required")]
    public string Job_no { get; set; }
    public string Client { get; set; }
    [DataType(DataType.Date,ErrorMessage="Invalid Date")]
    public DateTime ExpireDate { get; set; }


    IEnumerable<ValidationResult> IValidatableObject.Validate(ValidationContext validationContext)
    {
        List < ValidationResult >  res =new List<ValidationResult>();
        if (ExpireDate < DateTime.Today)
        {
            ValidationResult mss=new ValidationResult("Expire date must be greater than or equal to Today");
            res.Add(mss);

        }
        return res; 
    }
}